4L60E EPC solenoid
Thread Starter
TECH Enthusiast
Joined: Jan 2019
Posts: 677
Likes: 490
From: Roxana, IL
4L60E EPC solenoid I know the HZ operating signal changed on the 4L60E from 292.5 HZ to 5XXHZ but cant remember the exact #'s I can't find any information...
Does anyone remember off hand?
Does anyone remember off hand?
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
According to "If you look through any GM literature on early GM four speed transmissions, they clearly state the EPC solenoid had a frequency of 292.5Hz. This means that the EPC is pulsed 292.5 times per second. This was later changed to 585 Hz."
On this site: https://go4trans.com/technical-trans...cy-duty-cycle/
Your answer is 585.
Frankly I had no idea the EPC was PWM. I thought "PWM" on the trans referred to the lockup solenoid.
Always good to learn new stuff.
On this site: https://go4trans.com/technical-trans...cy-duty-cycle/
Your answer is 585.
Frankly I had no idea the EPC was PWM. I thought "PWM" on the trans referred to the lockup solenoid.
Always good to learn new stuff.
Thread Starter
TECH Enthusiast
Joined: Jan 2019
Posts: 677
Likes: 490
From: Roxana, IL
According to "If you look through any GM literature on early GM four speed transmissions, they clearly state the EPC solenoid had a frequency of 292.5Hz. This means that the EPC is pulsed 292.5 times per second. This was later changed to 585 Hz."
On this site: https://go4trans.com/technical-trans...cy-duty-cycle/
Your answer is 585.
Frankly I had no idea the EPC was PWM. I thought "PWM" on the trans referred to the lockup solenoid.
Always good to learn new stuff.
On this site: https://go4trans.com/technical-trans...cy-duty-cycle/
Your answer is 585.
Frankly I had no idea the EPC was PWM. I thought "PWM" on the trans referred to the lockup solenoid.
Always good to learn new stuff.
The TCC has both an on off solenoid and a PWM solenoid. The PWM is usually disabled by modifying that portion of the system. People either block it, use a TransGo SK, a Fitzall blocker valve or a Sonnax valve. Then that PWM solenoid is just there to supply an Ohms reading to the PCM.
TECH Junkie
Joined: Dec 2012
Posts: 3,614
Likes: 1,326
From: Iowa
PWM=Pulse Width Modulation
As for the EPC
They did change the frequency, but I have interchanged these solenoids with no ill effects.
I have used the early EPC in a late trans.
And a late EPC in an early trans.
Have not had any failures, codes, etc
As for the EPC
They did change the frequency, but I have interchanged these solenoids with no ill effects.
I have used the early EPC in a late trans.
And a late EPC in an early trans.
Have not had any failures, codes, etc
Thread Starter
TECH Enthusiast
Joined: Jan 2019
Posts: 677
Likes: 490
From: Roxana, IL
I am adding a way to control the EPC solenoid to my stand alone shift box. I just wanted to set the hertz to the proper frequency. I also know it runs 1.1 amp low pressure to .1amp high pressure. It's the HZ & duty cycle that I have to set up in the control box. The duty cycle runs @ +5% for minimum pressure & +40% for maximum pressure. The information I have doesn't elude to the current HZ that they run at. If I am not mistaken they only used the 292.5hz in the prom chipped PCM's and all the newer one's used the 585hz and I cannot say if it really truly matters or not.
Here's why I like the box. When I get a customer complaint about shift quality & function. I can go slap the box on & show them it's the car/tune and not my transmission. Showing them speaks so loud that everything they say becomes null & void...
I built my own box 20 years ago but could only operate at full line and I just don't like that. Using a scan tool serves the same purpose. It just doesn't have the same impact to the customer. The box is an in your face disconnect from their car. The box uses the accessory plug for power and ground I also have a battery connect extension for inactive accessory plugs.
Next will be the control of the TCC solenoid for the 4L80E.
